Heidelberg 2015 – wissenschaftliches Programm
UP 13.19: Poster
Donnerstag, 26. März 2015, 10:45–19:45, G/Foyer
reconstruction of Arctic surface temperature in past 100 years using DINEOF — •Qiyi Zhang — Center for Earth System Science, Tsinghua University, Beijing, China
Global annual mean surface temperature has not risen apparently since 1998, which was described as global warming hiatus in recent years. However, measuring of temperature variability in Arctic is difficult because of large gaps in coverage of Arctic region in most observed gridded datasets. Since temperature risen in Arctic is faster than global mean, the unobserved temperature in central Arctic will result in cold bias in both global and Arctic temperature measurement compared with model simulations and reanalysis datasets. Data Interpolating Empirical Orthogonal Function (DINEOF) were applied to fill the coverage gap in Arctic of NASA's Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP 250km smooth) product and reconstruct Arctic temperature in past 100 years. This method provided temperature reconstruction in central Arctic and precise estimation of global and Arctic temperature variability with a long temporal scale. Results have been verified by extra observed records of stations in Arctic.The amplification in polar region is more significant in reconstruction in recent 30 years, as the trend in Arctic since 1997 is 0.76°C per decade, compared with 0.48°C and 0.67°C per decade from 250km smooth and 1200km smooth of original GISTEMP. And global temperature trend is two times greater after using DINEOF. The result indicates that global warming in these years is not as slow as thought.